Differential Clunk.. Need Help!!

[JetBlack_M3]

What's happening guys. Up until 3 weeks ago my car started making a clunking sound upon acceleration like a baseball bat banging against the shaft. Even when in cruising speed, pressing and decompressing the gas pedal, I can hear a clunk sound anytime I let off. My driveshaft was inspected and was apparently in good condition.

I'm running Turner solid Delrin diff. bushings and I'm assuming they put a ton of stress on my differential and damaged it. Could this issue be from the u-joint on the driveshaft or a diff. Issue.

I included a video link down below so you guys can get an idea. Even with the driveshaft disconnected, it still made this sound. Assuming my diff is bad? Car is a 6MT

[Bubbles]

Originally Posted by boussi33

What's happening guys. Up until 3 weeks ago my car started making a clunking sound upon acceleration like a baseball bat banging against the shaft. Even when in cruising speed, pressing and decompressing the gas pedal, I can hear a clunk sound anytime I let off. My driveshaft was inspected and was apparently in good condition.

I'm running Turner solid Delrin diff. bushings and I'm assuming they put a ton of stress on my differential and damaged it. Could this issue be from the u-joint on the driveshaft or a diff. Issue.

I included a video link down below so you guys can get an idea. Even with the driveshaft disconnected, it still made this sound. Assuming my diff is bad? Car is a 6MT

Could be you cv joint binding. U joints go, center bearings and guibio. There are two options for you. Buy a new driveshaft which is easy but expensive or start replacing parts and hope that you find the culprit early.

[anerbe]

Start cheap and replace items that are known to wear out first.

- Center Support Bearing
- Flex disc
- Grease spines in driveshaft

Then you can start replacing other parts. Mine clunked moving back and forth under the car manipulating by hand, but doing the top 3 removed the cow bell noise when driving.

[JetBlack_M3]

Originally Posted by anerbe

Start cheap and replace items that are known to wear out first.

- Center Support Bearing
- Flex disc
- Grease spines in driveshaft

Then you can start replacing other parts. Mine clunked moving back and forth under the car manipulating by hand, but doing the top 3 removed the cow bell noise when driving.

Thank you. Ill give those a try

[Willem3]

I think your diff has bearing play, you can see and hear in in the movie.
The variable lock lsd is known for developing play.

I have installed a rebuild diff with the ZF lsd, much stronger construction and no more clunk or play

[JetBlack_M3]

Originally Posted by Willem3

I think your diff has bearing play, you can see and hear in in the movie.
The variable lock lsd is known for developing play.

I have installed a rebuild diff with the ZF lsd, much stronger construction and no more clunk or play

I purchased a used diff with 55k miles on it. When twisting it by hand, it doesn't seem to make the clunk sound that mine makes. As far as the clunk sound when letting off the clutch and accelerating, im starting to believe the sound is from my driveshaft Ujoint or possibly the CV

[drrust]

Either drive shaft or possible differential bolts.


Breaking axles (universals) https://www.m3post.com/forums/showthread.php?t=1710923

[pbonsalb]

Some say the variable lock diff is simply clunky. And that it can wear out at relatively low miles. There have a long diff thread reviewing a bunch of diff options. The main contributor is extremely knowledgeable. He recommends rebuilding with an older style fixed LSD.

[tdott]

try this first:
https://www.m3post.com/forums/showthread.php?t=1638255

The bolt that holds the two piece driveshalf together can get loose causing the metallic clack noise on accel/decel.

Commonly mis-diagnosed as a bad CSB which requires taking the two pieces apart, hence tightening that bolt when it goes back together. Then the owner thinks the CSB solved it when there was nothing wrong with it.

It can be tightened with the ds still in the car, just remove the xpipe and shields, with the right wrench you can get in there.

This wont fix the drive-line slop, but that is not causing the noise.